The present invention comprises improvements in fluid level detection and control means. Control of pumping apparatus in response to fluid level is referred to as "pump-off control means." Various mechanical, electro-mechanical, and electronic apparatus have been proposed for controlling the action of a pump located downhole in a borehole. Some apparatus are extremely complex in nature and invariably monitor various perimeters directly and indirectly associated with pumping action. The present invention avoids use of these indirect measurements employed by the prior art and goes directly to the heart of the problem, namely, directly measuring the distance from the surface of the ground to the fluid level, which also is a measure of the fluid level respective to the fluid-bearing formation and hence to the sub-surface pump itself.